The operation of cellular communication systems is fairly well known. A mobile station, such as a cellular telephone, has the ability to roam to other cellular systems, i.e., a cellular system other than its home system (the home system being the cellular system in which the user of the mobile station has an account), and place and/or receive calls. However, a roaming mobile station will incur roaming charges, and possibly long distance charges, when placing or receiving calls of any type, i.e., calls to/from land-lines, calls to/from other mobile stations, calls to/from groups, etc. Such roaming charges may be as high as 10.times. the normal rate per minute charge that would be incurred if the mobile station were communicating in its home system.
In the case of a company providing mobile stations to its employees for work use, the company may not wish the employee to originate or receive calls when the employee takes a mobile station out of its home system. Presently, a company has the following choices in how it may limit calls originating from its mobile stations: (1) Allow all (can dial any number); (2) Restrict all (can't dial any number); (3) Local calls+800# only (thus restricts all roaming calls); (4) Memory only; (5) Local calls+800#+ Memory only; (6) Restrict international calls, (7) Restrict 900# calls, and (8) Restrict operator calls.
With respect to receiving calls at the mobile station, a company has only two choices, namely, it can either (1) allow all incoming calls, or (2) prohibit all incoming calls.
Thus, a company attempting to restrict the use of its mobile stations by its employees is limited in its choices. In order to prohibit a mobile station from originating roaming calls, the company's only choice is to limit the mobile station to originating local and 800# calls. However, this means that the employee cannot make any long distance calls from the mobile station even though the company may wish the employee to be able to dial certain particular numbers at any time. While the company could store these particular numbers in the memory of the mobile station and restrict the employee to the memory only dial lock feature, this restricts the employee to dialing out to only the phone numbers stored in the memory, which may also be undesirable to the company.
A company wishing to restrict the receipt of calls by its mobile stations while they are roaming has even fewer choices. The company must either allow the mobile station to receive all incoming calls, including roaming calls, or restrict all calls to the mobile station, thus rendering the employee unreachable through his/her mobile station.
The present invention is directed toward overcoming one or more of the above-mentioned problems.